The aim of the present paper is to set the text of two Polish civil law provisions against the background of cognitive assumptions about language. The notion employed for the analysis are scenario, also called Idealized Cognitive Model or ICM (Lakoff 1987, Taylor 1989) and metonymy. The author's purpose is to prove that prototypical and non-prototypical understanding of legal terms in the texts of the mentioned provisions is an aspect of legal casuistry, i.e. the interpretation of legal rules to cover different possible situations (legal cases). The prototype-based reasoning in law texts is a desired state rather than a reality. (Krzysztof Kosecki)